Field of the Invention and Related Art
This invention relates to a process cartridge detachably attachable to the main body of an electrophotographic image forming apparatus, an image forming apparatus and an image forming system. Here, the process cartridge refers to electrifying means, developing means or cleaning means as process means and an electrophotographic photosensitive member integrally made into a cartridge which is made detachably attachable to the main body of the image forming apparatus. Or it refers to at least one of electrifying means, developing means and cleaning means as process means and an electrophotographic photosensitive member integrally made into a cartridge which is made detachably attachable to the main body of the image forming apparatus. Further, it refers to at least developing means as process means and an electrophotographic photosensitive member integrally made into a cartridge which is made detachably attachable to the main body of the image forming apparatus.
Also, the term xe2x80x9celectrophotographic image forming apparatusxe2x80x9d covers, for example, an electrophotographic copying machine, an electrophotographic printer (such as an LED printer or a laser beam printer), an electrophotographic facsimile apparatus and an electrophotographic word processor.
In an image forming apparatus using the electrophotographic image forming process, there has heretofore been adopted a process cartridge system in which an electrophotographic photosensitive member and process means for acting on the electrophotographic photosensitive member are integrally made into a cartridge which is made detachably attachable to the main body of the image forming apparatus. According to this process cartridge system, the maintenance of the apparatus can be done by a user himself without resort to a serviceman and therefore, the operability of the apparatus could be markedly improved. So, this process cartridge system is widely used in image forming apparatuses.
The developing apparatus of this process cartridge has a toner container which is a developer container for containing therein a toner which is a developer, and a developing chamber provided with a developing roller which is a developer carrying member. When the toner in the toner container is used up, the process cartridge needs be interchanged with a new one.
Also, in recent years, the digitization of copying machines and the use of plain paper in facsimile machine have advanced and a laser beam printer, a copying machine and a facsimile apparatus are sometimes constituted by a common printer portion. Products having these common printers need to have their functions changed a little depending on the ways of use of the respective products. For example, in the laser beam printer and copying machine, even if there is not the detection of the remaining amount of toner, the process cartridge can be interchanged at a point in time at which the toner in the toner container has become null and an image has become thin or blurred, and this does not become a great impediment. In the facsimile apparatus, however, there is a way of use, such as reception in the nighttime or the like, and therefore, if the apparatus is left in a state in which the toner in the toner container is about to become null, a thin output which is illegible may be put out. Consequently, a toner remaining amount apparatus for detecting the remaining amount of toner is requisite. Also, many copying machines that have been digitized in recent years also have the fax function and in this case, the toner remaining amount detecting apparatus becomes necessary even in the copying machines.
The above-mentioned toner remaining amount detecting apparatus is provided with a metallic antenna rod provided in a path leading from the toner container to a developing roller in the developing chamber in parallel to the lengthwise direction of the developing roller. A voltage is applied to between this antenna rod and the developing roller and the capacitance between the two is measured, whereby the remaining amount of toner can be detected. A predetermined threshold value is provided, and when the detected capacitance becomes lower than the threshold value, it can be known that the toner between the two is small, that is, the amount of toner in the container is small. In this manner, changes in the capacitance are detected to thereby detect the exhaustion of the toner.
As regards process cartridges for use in a group of such products, the ones for use in the facsimile apparatuses need have the toner remaining amount detecting function attached thereto, and the ones for the others need not have the toner remaining amount detecting function. Therefore, two kinds of process cartridges had to be prepared. These two kinds of process cartridges must be non-interchangeable with each other. Therefore, it would occur to one""s mind to provide convex and concave shapes on respective frames, and provide a concavity and a convexity at corresponding locations on the main body of the image forming apparatus.
It is an object of the present invention to provide a process cartridge, an electrophotographic image forming apparatus and an electrophotographic image forming system which can prevent a process cartridge from being wrongly attached to the main body of a functionally different electrophotographic image forming apparatus.
It is another object of the present invention to provide a process cartridge, an electrophotographic image forming apparatus and an electrophotographic image forming system in which a cartridge abutting portion provided on a process cartridge has both of the function of moving a laser shutter to a retracted position for opening a laser optical path and the function of preventing the process cartridge from being wrongly attached to the main body of a functionally different image forming apparatus.
It is another object of the present invention to provide a process cartridge, an electrophotographic image forming apparatus and an electrophotographic image forming system provided with a cartridge abutting portion which enables an operator to visually confirm wrong attachment when he tries to attach a process cartridge to a functionally different electrophotographic image forming apparatus.
It is another object of the present invention to provide a process cartridge, an electrophotographic image forming apparatus and an electrophotographic image forming system which have realized non-interchangeability by a simple construction like a projection protruded upwardly from the cleaning frame of the process cartridge.
It is another object of the present invention to provide a process cartridge detachably attachable to the main body of an electrophotographic image forming apparatus having a laser beam applying member, a shutter for shutting off the optical path of a laser beam emitted from the laser beam applying member, a main body abutting portion for moving the shutter to a retracted position retracted from a shutting-off position for shutting off the optical path, a main body frame provided upstream of the shutter with respect to the attachment direction of the process cartridge, and an opening portion provided in the main body frame, the process cartridge having:
an electrophotographic photosensitive drum;
process means for acting on the electrophotographic photosensitive drum; and a process cartridge abutting portion adapted, when the process cartridge is to be attached to the main body of an electrophotographic image forming apparatus functionally differing from the main body of the image forming apparatus, to abut against a main body frame provided on the main body of the functionally different image forming apparatus to thereby block the attachment of the process cartridge, and when the process cartridge is to be attached to the main body of the image forming apparatus, to pass through the opening portion and abut against the main body abutting portion to thereby move the shutter to the retracted position.
It is another object of the present invention to provide an electrophotographic image forming apparatus for permitting one of a plurality of process cartridges to be detachably attached thereto and forming an image on a recording medium, comprising:
(i) a laser beam applying member;
(ii) a shutter for shutting off the optical path of a laser beam emitted from the laser beam applying member;
(iii) a main body abutting portion for moving the shutter to a retracted position retracted from a position for shutting off the optical path;
(iv) a main body frame provided upstream of the shutter with respect to the attachment direction of the process cartridge;
(v) an opening portion provided in the main body frame;
(vi) a cleaning frame, an electrophotographic photosensitive drum supported by the cleaning frame, an exposure opening formed in the cleaning frame to apply the laser beam to the electrophotpgraphic photosensitive drum, and a cartridge abutting portion protruding upwardly from the cleaning frame with the process cartridge attached to the main body of the apparatus, and provided on one end portion of the exposure opening in the axial direction of the photosensitive drum, the cartridge abutting portion being adapted, when the process cartridge is to be attached to the main body of an electrophotographic image forming apparatus functionally differing from the main body of the image forming apparatus, to abut against a main body frame provided on the functionally different main body to thereby block the attachment of the process cartridge, and when the process cartridge is to be attached to the main body, to pass through the opening portion and abut against the main body abutting portion, whereby when the process cartridge is attached to the main body, the corner and upper portion of the distal end of the cartridge abutting portion abuts against the main body abutting portion to thereby move the shutter to the retracted position; and
(vii) conveying means for conveying the recording medium.
It is another object of the present invention to provide an electrophotographic image forming system for attaching a process cartridge to the main body of an electrophotographic image forming apparatus, and forming an image on a recording medium, the main body of the image forming apparatus comprising:
a laser beam applying member;
a shutter for shutting off the optical path of a laser beam emitted from the laser beam applying member;
a main body abutting portion for moving the shutter to a retracted position retracted from a shutting-off position for shutting off the optical path;
a main body frame provided upstream of the shutter with respect to the attachment direction of the process cartridge;
an opening portion provided in the main body frame;
attaching means for detachably attaching the process cartridge; and
conveying means for conveying the recording medium;
the process cartridge comprising:
an electrophotographic photosensitive drum;
process means for acting on the electrophotographic photosensitive drum; and
a cartridge abutting portion adapted, when the process cartridge is to be attached to the main body of an electrophotographic image forming apparatus functionally differing from the main body of the image forming apparatus, to abut against a main body frame provided on the functionally different main body of the image forming apparatus to thereby block the attachment of the process cartridge, and when the process cartridge is to be attached to the main body of the image forming apparatus, to pass through the opening portion and abut against the main body abutting portion to thereby move the shutter to the retracted position;
wherein when the process cartridge is to be attached to the main body of the electrophotographic image forming apparatus functionally differing from the image forming apparatus, the main body frame provided on the functionally different main body of the image forming apparatus and the cartridge abutting portion abut against each other to thereby block the attachment of the process cartridge, and when the process cartridge is to be attached to the attaching means, the cartridge abutting portion passes through the opening portion and abuts against the main body abutting portion to thereby move the shutter to the retracted position.